This view of the twilight sky and Martian horizon taken by NASA's Curiosity Mars rover includes Earth as the brightest point of light in the night sky. Earth is a little left of center in the image, and our moon is just below Earth.

This frame from an animation from NASA's Mars rover Curiosity shows the rover drilling into rock target 'Cumberland.' The drilling was performed during the 279th Martian day, or sol, of the Curiosity's work on Mars (May 19, 2013).

This image from the Mars Hand Lens Imager on NASA's Mars rover Curiosity shows the patch of rock cleaned by the first use of the rover's Dust Removal Tool (DRT). The tool is a motorized, wire-bristle brush on the turret at the end of the rover's arm.

The two bodies in this portion of an evening-sky view by NASA's Mars rover Curiosity are Earth and Earth's moon. The rover's Mast Camera (Mastcam) imaged them in the twilight sky of Curiosity's 529th Martian day, or sol (Jan. 31, 2014).

An instrument suite that will analyze the chemical ingredients in samples of Martian atmosphere, rocks and soil during the mission of NASA's Mars rover Curiosity, is shown here during assembly at NASA Goddard Space Flight Center, Greenbelt, Md., in 2010.

Before NASA's Curiosity rover landed on Mars, the strata exposed in Mount Sharp were compared to those in the Grand Canyon of the western United States, shown here. Scientists are surprised by just how close the similarities are.

This image shows the tracks left by NASA's Curiosity rover on Aug. 22, 2012, as it completed its first test drive on Mars. This image was taken by a front Hazard-Avoidance camera, which has a fisheye lens.

This 360-degree panorama shows evidence of a successful first test drive for NASA's Curiosity rover; the rover made its first move, going forward about 15 feet (4.5 meters), rotating 120 degrees and then reversing about 8 feet (2.5 meters).

This is the first laser spectrum from the ChemCam instrument on NASA's Curiosity rover, sent back from Mars on Aug. 19, 2012, showing emission lines from different elements present in the target, a rock near the rover's landing site dubbed 'Coronation.'

This image of NASA's Curiosity rover shows the location of the two components of the Dynamic Albedo of Neutrons instrument. The neutron generator is mounted on the right hip and the detectors are on the opposite hip.

This graph shows readings for atmospheric pressure at the landing site of NASA's Curiosity rover. The data were obtained by Curiosity's Rover Environmental Monitoring Station from Aug. 15 to Aug. 18, 2012.

With the addition of four high-resolution Navigation Camera, or Navcam, images, taken on Aug. 18 (Sol 12), Curiosity's 360-degree landing-site panorama now includes the highest point on Mount Sharp visible from the rover.

The Curiosity engineering team created this cylindrical projection view from images taken by NASA's Curiosity rover rear hazard avoidance cameras underneath the rover deck on Sol 0. Pictured here are the 'pigeon-toed' wheels in their stowed position from